Which strait separates Alaska from Russia?

The Bering Strait, about 82 kilometres wide - and in the middle sit two islands, Big Diomede in Russia and Little Diomede in the United States, roughly four kilometres apart with the international date line between them. It is tomorrow on one and today on the other, and in a hard winter the water between them freezes.

It is also the route by which the Americas were populated. During the last glacial maximum, sea level was low enough that the strait was a plain hundreds of kilometres wide - Beringia, which was not a bridge to be crossed quickly but a habitable region where populations appear to have lived for thousands of years before moving south. Genetic evidence supports that pause, and the coastal route may have mattered as much as the interior one.

The two Diomedes have a small human tragedy attached. The islands' Inupiat communities were closely related and visited each other freely until the Cold War closed the border - the Russian population was relocated to the mainland and families were separated for decades. The strait has been proposed repeatedly for a bridge or tunnel, and the engineering is the easy part compared with what would sit at either end: on both sides, hundreds of kilometres of nothing.